So, it's happened. Congress could not agree on a budget and the U.S. federal government has shut down all non-essential services. Hundreds of thousands of government workers have been furloughed without knowing when they will return to work.

Oh my God! Oh my God! I saw this on "Doomsday Preppers." Total collapse! I knew I should have built that bomb shelter and started hoarding lentils.

Cool your jets. This is far from the apocalypse. The government has not ground to a complete halt. Services deemed essential like Medicare, mail delivery, tax collection and the military will continue to operate. Non-essential departments and employees, like national park rangers and NASA staff (who aren't currently in orbit) will be furloughed. Also, the National Zoo will be closed.

Someone is going to get a very angry tweet about this! If only I knew who to blame… and also how this happened.

Every year Congress has to agree on a budget to fund the government. The fiscal year ended on Sept. 30, but Congress was unable come to a consensus about how best to use federal funds. Without a budget – essentially a law passed by both the House of Representatives and the Senate -- to pay employees and fund programs for the new fiscal year, the government effectively shut down at midnight on Oct. 1.

Despite several last minute attempts, lawmakers could not even agree to a stopgap measure that would fund the government temporarily.

Those guys can never agree on anything. And now they're going to let all the animals at the National Zoo starve to death. Those poor pandas! Why couldn't they just make a deal?

Firstly, all of the animals will be fed and taken care of. The pandacam, however, will be shut down.

The sticking point in the negotiations was funding the Affordable Care Act, or Obamacare, the president's signature piece of legislation that would increase the number of Americans who receive health insurance by requiring them to buy it.

The House is controlled by Republicans, whose Tea Party faction is wholly opposed to Obamacare. They've tried to use the budget as leverage to defund or delay Obamacare.

Every budget they sent to the Senate for approval was bounced back, because the Senate is controlled by Democrats who want see Obamacare succeed.

So after all that Obamacare is going to be defunded anyway?

No. Obamacare will not be affected by the shutdown. In fact, the online marketplaces to buy insurance went live at midnight, just as the rest of the government shut down.

I'm sure this sort of thing has never happened before. I would have heard about the zombies.

There won't be any zombies. (Hopefully, anyway. The CDC is shutting down.) But, there have been shutdowns in the past, usually not lasting more than a few days at a time. The most recent shutdown was in 1996, when President Bill Clinton and House Republicans led by Speaker Newt Gingrich could not reach a deal. That shutdown lasted nearly a month.

So now what happens?

We have to wait for one side to blink and agree to cut a deal. Lawmakers are back at it today. On Monday night the House decided to form a "bipartisan committee" to come up with a proposal, but if any part of that deal includes defunding Obamacare, the Senate will reject it. Federal employees will continue to go unpaid until a budget is struck.

But in the meantime, all Americans can just break the law free of consequence and don't have to go work?